GPIO: MIPS: lantiq: move gpio-stp and gpio-ebu to the subsystem folder

Move the 2 drivers from arch/mips/lantiq/xway/ to the subsystem and make them
buildable.

The following 2 patches will convert the drivers to OF.

Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Patchwork: https://patchwork.linux-mips.org/patch/3838/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index e03653d..8fae079 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -96,6 +96,14 @@
 	depends on ARCH_EP93XX
 	select GPIO_GENERIC
 
+config GPIO_MM_LANTIQ
+	bool "Lantiq Memory mapped GPIOs"
+	depends on LANTIQ && SOC_XWAY
+	help
+	  This enables support for memory mapped GPIOs on the External Bus Unit
+	  (EBU) found on Lantiq SoCs. The gpios are output only as they are
+	  created by attaching a 16bit latch to the bus.
+
 config GPIO_MPC5200
 	def_bool y
 	depends on PPC_MPC52xx
@@ -306,6 +314,16 @@
 	  This enables support for the GPIOs found on the STMPE I/O
 	  Expanders.
 
+config GPIO_STP_XWAY
+	bool "XWAY STP GPIOs"
+	depends on SOC_XWAY
+	help
+	  This enables support for the Serial To Parallel (STP) unit found on
+	  XWAY SoC. The STP allows the SoC to drive a shift registers cascade,
+	  that can be up to 24 bit. This peripheral is aimed at driving leds.
+	  Some of the gpios/leds can be auto updated by the soc with dsl and
+	  phy status.
+
 config GPIO_TC3589X
 	bool "TC3589X GPIOs"
 	depends on MFD_TC3589X